One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,5)(4,6)(7,8)(9,10)(11,16)(12,13)(14,15)(17,18)(19,23)(20,21)(22,24)(25,26)(27,33)(28,36)(29,32)(30,35)(31,37)(34,38)(39,40) involution — undirected(2,3)(4,8)(9,11)(10,13)(12,14)(15,16)(18,21)(19,24)(25,26,29,32)(27,30,35,33)(28,36,37,31)(34,39,40,38)(2,3)(6,7)(10,15)(11,12)(17,18,20,21)(19,22,24,23)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,37)(38,40)(1,3,5,2)(4,7,8,6)(9,12,14,11)(10,16,15,13)(17,18)(19,22)(20,21)(23,24)(25,27)(26,30)(28,34)(29,35)(31,38)(32,33)(36,39)(37,40)(1,4)(2,6)(3,7)(5,8)(9,13,14,16)(10,11,15,12)(17,19,20,24)(18,22,21,23)(25,28)(26,31)(27,34)(29,37)(30,38)(32,36)(33,39)(35,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.